1. Field of the Invention
This invention is directed to a method for quantitatively determining the extent of mold contamination of grain and other food in storage. More particularly, the invention is directed to a method for quantifying storage mold contamination by selectively extracting mold spores from the stored commodity with a solvent, such as a paraffinic hydrocarbon or an aqueous detergent solution and determining the number of mold spores by quantitative microbiological procedures.
One of the most severe problems in the grain and food industry is the contamination and resulting deterioration of these stored commodities by fungi. Much research has been devoted to identifying conditions under which storage molds flourish, and the results of this research have pointed to ideal means of storing grain and other mold-susceptible bulk food to reduce losses. These preventative technologies, however, are expensive when generally applied to all stored commodities and their objectives are not always attained in practice. One of the major needs in applying existing preventative technologies is a reliable, sensitive means for assessing the extent of initial mold contamination of grain or food before transfer to storage and for monitoring development or increase in mold contamination during storage.
The most common and economically important group of grain storage molds is in the genus Aspergillus. The two common approaches for assessing contamination with this organism are (1) transfer of individual seeds to a mycological nutrient medium to observe the number of seeds from which fungi grow, and (2) pooling and grinding of a seed sample before transfer to mycological nutrient medium to observe the number of particles from which storage molds grow. The problem with the first approach is that only very small numbers of seeds can be processed feasibly. The second approach does not allow one to know whether one or a few seeds within the larger sample were heavily contaminated, or whether all the seeds were contaminated but to a lower extent. Importantly, neither method discriminates between light and heavy mold infestations. What is required instead is a means of assessing quantitatively the total load of storage molds in a relatively large sample of stored grain or other bulk stored food. Ideally, this procedure should be not only sensitive but sufficiently rapid and convenient to permit processing of replicate samples of the same lot of stored grain or food.
Members of the genus Fusarium may infest certain grains and under appropriate circumstances produce potent toxins that are hazardous to humans and livestock. No effective method is known for quantitatively determining Fusarium infestation.
2. The Prior Art
No prior art pertinent to the claimed method of quantifying storage mold contamination is known to applicant.